中文摘要：

在100mmol／L NaCl胁迫下，研究了外源多胺-腐胺（Put）、尸胺（Cad）、亚精胺（Spd）和精胺（Spm）对玉米幼苗生长、光合速率和PSⅡ光化学效率（Fv／Fm）、叶绿体结合多胺和叶片丙二醛（MDA）含量以及抗氧化酶活性的影响。结果表明，叶面喷施1mmol／L的Put、Spd和Spm可显著增加盐胁迫下玉米幼苗干物质重、叶绿体内结合态多胺的含量、叶片净光合速率和PsⅡ光化学效率（Fv／Fm），并降低了叶片中MDA含量。外源Spd和Spm明显增加盐胁迫下玉米幼苗的抗坏血酸过氧化物酶（APX）、过氧化物酶（POD）和过氧化氢酶（CAT）活性；外源Put可增强APX和POD活性，对CAT活性的影响不明显。这些结果表明多胺对玉米盐害的缓解作用可能是由于提高了叶绿体中结合态多胺的含量和叶片抗氧化酶的活性，从而增强了盐胁迫下的玉米光合能力。

英文摘要：

The effects of putrescine, cadaverine, spermidine and spermidine on the growth, photosynthetic rates,PS Ⅱ photochemical efficiency （Fv/Fm）,chloroplast-bound polyamine contents and MDA content and anti-oxidative enzyme activities of corn seedlings under 100 mmol/L NaCl stress were studied. The results showed that topdressings of putrescine,cadaverine,spermidine and spermidine could significantly increase the dry matters ,chloroplast-bound polyamine contents,net photosynthetic rate and PS Ⅱ photochemical efficiency of corn seedlings but reduce the MDA content of the seedlings. Exogenous polyamines could significantly increase the APX,POD,CAT activities in corn seedlings suffering salt stress ;exogenous putrescine can enhance the APX and POD activities,but exerted insignificant influence on the CAT activity. These make it clear that the alleviation of salt damage by polyamines is probably because increased chloroplastbounded polyamine contents and anti-oxidative enzyme activities help enhance the photosynthetic capacities of corn suffering salt stress.